1. Field of the Invention
The present invention relates to a fiber-optic measuring device for measuring a physical quantity, comprising a transducer unit and an electronic unit interconnected by an optic fiber.
2. Description of the Prior Art
A large number of physical and chemical measurements may be effected using an optical transducer influenced by the quantity to be measured to modulate the light transmission. To transmit the light intensity variations caused by the transmission changes, without degradation of the accuracy of measurement, in a fiber-optic measuring system, systems with wavelength demultiplexing and spectral light division in the transducer have been developed. These measuring systems require a relatively complicated optical system in the transducer unit, while at the same time great demands are placed on the optoelectronics in the measuring electronic unit.
Many optical effects, which are well suited for measuring physical quantities, involve a change of the light transmission of a sensor material. To fiber-optically sense these transmission changes with sufficient accuracy for measuring purposes, requires the provision of means for compensating for varying attenuation and light reflection in the optical system.